Still reeling over the end of his relationship with Kourtney Kardashian, Scott Disick fears what will undoubtedly be the hardest part of their split: custody arrangements.

Still handling the heartbreak from the loss of a 9-year love affair, Kourtney Kardashian, 36, and Scott Disick, 32, reunited for a brief lunch on July 23. No, not to rekindle their romance, but to talk about the future of their three kids, Mason, 5, Penelope, 3, and Reign, 6 mos. While they didn’t discuss a custody agreement just yet, Lord Disick can see it on the horizon — and is absolutely dreading it, a source tells HollywoodLife.com EXCLUSIVELY.

“No formal arrangements with regard to child custody have been made yet. They both know they have to sit down and discuss their future, something Scott doesn’t really want to face right now,” a source tells HollywoodLife.com EXCLUSIVELY. “He explained to Kourtney that he’s going to Vegas for work, for money and that his trip has nothing to do with him partying or hooking up.”

With talk of custody impending, Kourtney is at a loss for what to tell her little ones about the whole ordeal. With daddy no longer living at their Calabasas, CA manse anymore, the mom-of-three did her best to explain why he isn’t around.

“It took all her strength no to fall apart. It was difficult for them to grasp and truly heartbreaking for Kourtney,” a second insider reveals about the daunting discussion. “She made sure not to slam Scott to the kids because she knows how important it is for them to have positive feelings towards him even if she doesn’t.”

HollywoodLifers — what do YOU think about Scott not wanting to face Kourtney in a custody battle? Let us know your thoughts!